What type of movement does a snake have? Methods of movement of a snake. Can a snake crawl in the opposite direction?

Snakes don’t have legs or even their rudiments, but how do they manage to “run” so fast? Interest Ask. The snakes, having lost their limbs, returned to their old method of movement. It seems to us that the snake moves with the help of its abdominal scutes, catching them on the ground. But this is not true. Carefully observing the movement of the snake and having studied decanally the methods of its movement, it was found that they move in a very specific way, using the movement of the whole body. The snake bends its body in a horizontal plane, creating waves of bends that continuously follow from front to back, creating a force that moves the snake forward.

A perfectly flat surface serves as an obstacle to the movement of the snake. Snakes cannot crawl on glass or . But if there is even the slightest roughness, then movement is quite possible. According to this principle, snakes “walk” on the sand. When bending the body, the loose sand moves and forms folds, which help movement. True, the speed of movement is very slow.

When moving on a smooth surface, friction occurs between the front part of the body and the soil (static friction), the snake collects the body into an accordion and pulls its back part forward - sliding friction is less than static friction. Then, leaning on the tail of the snake, the front part of the body lunges forward and again contracts into an accordion. Large, heavy and heavy snakes use this method of movement. strong body. This is how boas, snakes and vipers “walk”.

There is another way for a snake to move. It is based on the difference between static friction and sliding friction. When crawling this way, the snake does not bend, and its body remains straight. Part of the scutes on its belly is fixed to the soil, and the other part is pulled forward by muscles. The movable shields are fixed, and those that were not movable are tightened. This “straightforward” method of movement is used by snakes with short and thick bodies, some of them are boas and blind snakes.

Both described methods of movement of snakes do not allow them to crawl quickly, although they allow them to overcome smooth surfaces. To move quickly, snakes use “lateral movement.” The lateral method of “walking” of snakes can only be observed in them, and other animals use other methods when moving.

When moving sideways, the snake, lying on the ground or sand, raises its head, and then the front part of the body, bends it at a right angle and places it in a new place. The emphasis is placed on two points, the snake does the same with the rest of the body, so in parts it moves its body forward and to the side as it moves. During such movement, traces remain in the sand in the form of imprints of the snake’s body; they are directed obliquely to the direction of movement. This is how snakes of the species walk - horned vipers, ephas, rattlesnakes who live in the sands.

There is no doubt that the imagination of nature significantly exceeds that of humans: amazing shapes, bright colors, all possible sizes of living and extinct representatives of flora and fauna often simply do not fit into the framework of our perception. But, unlike characters in science fiction books and films, in real organisms each of these expressive features is necessary to perform a particular function. This especially affects the method of movement.

Smooth fish scales covered with a thin layer of mucus; durable yet lightweight bird feathers; thin leathery membranes of flying lizards; cat claws; distant thumb in primates; numerous “finds” for upright walking, which people are so proud of; arthropods have six or even more pairs of legs. But each of these limbs needs to be controlled, and even balanced with the rest of the body, so that you don’t have to lift it again.

In this regard, snakes, worms and legless amphibians made the right choice - if you are already on the surface, then, in fact, you have nowhere to fall. But the mechanics of their movement turned out to be much more complicated than it seemed. David Hu of New York University and his colleagues

proved that characteristic crawling is ensured by the uneven distribution of friction force along the surface of the body in contact with the ground and the constant redistribution of weight.

This is how they fundamentally differ from their “brothers” in misfortune - worms and legless amphibians. The latter synthesize a copious amount of mucus, the worms push themselves forward, clinging to small hairs. But in the case of snakes, until recently, one could only rely on hypotheses.

According to one of them, the friction force in the longitudinal direction was significantly less than that in the transverse direction. If we add the ability to twist, the loops will provide the necessary stability, while moving forward will continue. A demonstration of this approach are wheeled robotic snakes, whose body moves easily forward and does not move sideways at all. However, they also need support points from which to build on. In the case of sand or bare stone, this approach will not work.

Authors publications in Proceedings of the National Academy of Sciences have significantly expanded the existing understanding of the movement of these reptiles. Their wards were 10 young milk snakes (Campbell's king snake or Lampropeltis triangulum campbelli). These snakes that live in North America, are known for being very similar in appearance to poisonous coral adders, although they themselves are much less dangerous.

To begin with, the experimenters euthanized the reptiles and measured the friction force in all directions.

As expected, when moving to the side it turned out to be almost twice as large, and backward - one and a half times, than when moving forward.

But this is only if the surface is rough. If something super-smooth acted as a substrate, then the friction force in all directions tended to zero. However, they did not expect a miracle from snakes - it would be strange to believe that scales cling differently to something that, in principle, is impossible to cling to.

The resulting model also explains the ability of snakes to move on an inclined surface and gives calculated speeds that are almost approaching real ones.

Dynamic load distribution during lateral bending. Top photo- A snake crawling across a mirror. This picture shows the "wave" used to redistribute the weight. Although this photo was taken for demonstration purposes (the surface is smooth, so the reptile hardly moves), the same phenomenon was observed when moving on rough surfaces. Below is the calculated driving force on models with uniform (middle row) and uneven ( bottom row) weight distribution. The red dot marks the center of mass, the black dots indicate the places of greatest pressure on the surface //David L.Hu et al., PNAS

Scientists explain the missing “kilometers per hour” by a kind of wave that the snake sends through its body. It was possible to register it by video recording movement on a mirror surface. In this case, reptiles do not completely tear off their body, but only reduce the load on certain areas, constantly moving the center of mass.

The authors even expect to find their discovery practical use- such robots in some cases are significantly superior to wheeled and even “six-fingered” robots. Wheels will be completely useless if the height of the obstacle is more than half the diameter of the wheel, and the limbs require much more room to maneuver than a thin flexible body. So, when clearing rubble or in reconnaissance, such robotic snakes can be of great use. All that remains is to learn how to make snake-like scales.

Methods of transportation

It may seem that it is very difficult to move without legs, but snakes do it masterfully. In fact, they know how to move on land in four main ways. If one method is not suitable, then they use another. Sometimes, especially on a very flat surface, they have to try all four methods. The crawling of snakes can be quite rapid, and some of them are even capable of chasing their prey. However, even the most fast snakes rarely reach speeds exceeding 8 km/h. The crawling speed record is 16-19 km/h and belongs to the black mamba.

1. Accordion movement
One way the snake moves is called an accordion movement. First, the snake gathers its body into folds. Then, holding the tip of the tail in place, he pushes the front of the body forward. And finally tightens the back of the body.

2. Track movement
With the help of the caterpillar movement, the snake can move in a straight line. She uses this movement when she needs to overcome some bottleneck. At the same time, the snake moves large scales located on its belly. One by one, the scales sink into the ground like small shovels. As soon as the scales sink into the ground, the muscles move them towards the tail. One by one, the scales are repelled from the ground, and due to this, the snake moves. This is the same method people use when they row while on a boat. They plunge their oars into the water just as snakes plunge their scales into the ground.

3. Twisting movement
Designed to move on hard ground. To move forward, the snake bends its body to the side, resting against stones, roots, sticks or other hard objects. During this movement, snakes alternately contract the muscles on their sides, so that their body bends in an S-shape: the snake wriggles and crawls.
Wave-like bending of the body is the most common way of snakes crawling. A calmly crawling snake is an amazingly beautiful and bewitching sight. Nothing seems to happen. The movements are almost imperceptible. The body seems to lie motionless and at the same time quickly flows. The feeling of ease of movement of a snake is deceptive. In her amazingly strong body, many muscles work synchronously and measuredly, moving the body precisely and smoothly. Each point of the body in contact with the ground alternately finds itself in the phase of either support, push, or forward transfer. And so constantly: support-push-transfer, support-push-transfer... What longer body, the more bends and the faster the movement. Therefore, during the course of evolution, the body of snakes became longer and longer. In this regard, they are record holders among vertebrate animals. The number of vertebrae in them can reach 435 (in humans, for comparison, only 32-33).

4. Twisting or sideways movement- This is a method of movement that is used only by some species of snakes living in the desert. Using this method, they can move quickly through loose sand, and they move so quickly that it is difficult to follow them. In this case, the snake’s head goes sideways and forward, and then the body is pulled up. Snakes begin to almost walk, if one can say so about completely legless creatures: leaning on the back part of the body, they carry the front part forward, then vice versa.
In this case, very strange marks appear in the form of oblique parallel stripes with hooks at the end. You wouldn’t immediately guess that such a trace could be left Living being! It is in this way that the sand faff moves - very dangerous snake, living here in Central Asia.

In addition to these methods, there are still some very unusual movement techniques. For example, in Indonesia, Indochina, and the Philippines, snakes from the genus Chrysopelea, a subfamily of false snakes, live. They are called heavenly for their grace and beauty. The paradise snake lives on palm trees, where it feeds on lizards. And if she wants to change her place of residence, she flies to another palm tree. When flying, its body takes on an S-shape, and its tail serves as a rudder. Before jumping, the snake takes a deep breath, forming an air chamber inside its body that serves as a kind of parachute and allows it to glide over a distance of up to 35 meters.

Some snakes are even capable of jumping forward, first gathering their body into rings, like a spring, and then sharply straightening it.

The muscular system of reptiles is represented by chewing, cervical, abdominal, and flexor and extensor muscles. There are intercostal muscles characteristic of higher vertebrates that play important role during the act of breathing. Subcutaneous muscles allow you to change the position of the horny scales.

Muscles of the head.

Due to the fact that snakes do not chew their prey, but swallow it whole, their chewing muscles do not achieve strong development and serve to open and close their jaws and hold prey with the help of numerous small teeth. The facial muscles are underdeveloped, so the lips and tip of the nose of snakes are practically motionless and have a strong connective tissue base.

Muscles of the spinal column.

This muscle group is highly developed and well differentiated. Snakes have the following groups multisegment muscles:

Longissimus muscles of the trunk and tail (m. longissimus trunci et coccygey) - These muscles provide extension of the spinal column and lateral movements of the trunk.

Interspinous muscles (m. interspinales) - They contribute to the extension of the spinal column.

Short intertransverse muscles (m. intertransversarii) - provide lateral movements of the body of snakes.

Rib levators m. levatori costarum) - These muscles are most developed in cobras in the cervical region and provide expansion of the neck with the formation of a “hood”.

snake suborder poisonous skeleton

Rib retractors m. retractors costarum) - begin at the proximal end of the rib, ending at the arch of the underlying vertebra.

Descenders of the ribs (m. depressores costarum) - begin on the ventral surface of the proximal end of the rib, ending on the ventral surface of the vertebral body.

Intercostal muscles (m. intercostals) - located between the ribs, highly developed.

The flexors of the spinal column (m. flexores) - highly developed, especially in boas and pythons, are located on the ventral surface of the vertebral bodies, spreading through several segments - these are the long muscles of the trunk and tail.

The strong development and elasticity of the described muscle groups ensures a serpentine type of movement, that is, movement using bends of the body and ribs that are not closed ventrally. In other words, snakes, writhing, “walk on their ribs.” When the snake makes a bend, the longissimus and intertransverse muscles on the side of the bend are tense, and on the side opposite the bend they are relaxed. During a forward lunge, these muscles are in the opposite functional state.

Movement

When the snake moves, each abdominal shield, with the help of the corresponding muscles, takes a position at right angles to the skin. With the shield in this position, the animal rests on the ground. One movement of the muscles - the shield is pressed to the skin, and the next one takes its place. During the movement of the snake, the shield behind the shield becomes an instant point of support and repulsion, and only thanks to them is it possible forward motion. The scutes serve the snake as if it were a hundred tiny legs.

The movements of the vertebrae, ribs, muscles and scutes are strictly coordinated; they occur in the horizontal plane. The raised head of the snake is lowered to the ground, then the loop of the front third of the body is pulled up; then the snake again moves its head forward to rest it on the ground again, make another forward movement and pull the whole body along with it. Until the snake gets a foothold, it is unable to move. The snake will not be able to move on the smooth surface of the glass, since the transverse shields will only slide along it.

If you follow a snake while it is X-rayed, you can see how complex the coordinated movements of its skeleton are. The spine easily bends in any direction and thanks to this, the snake’s body can either curl up into a ring, or rise by almost a third of its length above the ground, or rush forward with incredible speed.

Methods of movement of a snake

In fact, snakes can move on land in four main ways. If one method is not suitable, then they use another. Sometimes, especially on a very flat surface, they have to try all four methods. The crawling of snakes can be quite rapid, and some of them are even capable of chasing their prey. However, even the fastest snakes rarely reach speeds exceeding 8 km/h. The crawling speed record is 16-19 km/h and belongs to the black mamba.

1. Accordion movement.

First, the snake gathers its body into folds. Then, holding the tip of the tail in place, he pushes the front of the body forward. And finally tightens the back of the body.

2. Movement by caterpillar.

The snake can move in a straight line. She uses this movement when she needs to overcome some bottleneck. At the same time, the snake moves large scales located on its belly. One by one, the scales sink into the ground like small shovels. As soon as the scales sink into the ground, the muscles move them towards the tail. One by one, the scales are repelled from the ground, and due to this, the snake moves.

3. Twisting movement.

Designed to move on hard ground. To move forward, the snake bends its body to the side, resting against stones, roots, sticks or other hard objects. During this movement, snakes alternately contract the muscles on their sides, so that their body bends in an S-shape: the snake wriggles and crawls.

Wave-like bending of the body is the most common way of snakes crawling.

4. Coiling or lateral movement is a method of movement that is used only by some species of snakes living in the desert. Using this method, they can move quickly through loose sand. In this case, the snake’s head goes sideways and forward, and then the body is pulled up. The snakes begin to almost walk, if one can say so completely legless creatures: leaning on the back of the body, they bring the front forward, then vice versa.

5. Digging move.

These include, for example, blind snakes.

Many species of blind snakes have tiny eyes that can distinguish light from dark; some species have no eyes at all. A strong skull and large scutes on the front of the head help blind snakes build tunnels in the thickness of loose soil.

Snakes often take refuge underground from heat or cold. Others find the burrows of small animals and, climbing into them, eat their owners. For some desert snakes, sand provides excellent shelter. With only their head above its surface, they patiently wait for prey.

6. Woody appearance.

Many snakes are good at climbing branches of trees and bushes. But some species of snakes spend their entire lives in treetops. Such snakes are called arboreal snakes. When hunting for lizards, the Mexican sharp-headed snake often throws its body from branch to branch. In preparation for “flight,” the snake flattens its body, spreading its ribs greatly. This allows her to glide smoothly in the air.

The movement of snakes is full of charming originality. The sight of a silently sliding writhing ribbon makes an indelible impression on the viewer and provides aesthetic pleasure. However, the typical so-called “snake” movement is by no means the only way, which is used by snakes. IN different conditions habitat, on different substrates various snakes developed a number of special types of movement. With the “serpentine” type of movement, the body bends in a wave-like manner and the resulting waves seem to run along the body from head to tail. The arching part of the body, placed obliquely to the direction of movement, rests on the substrate and creates a pushing force. It is directed at an angle to the movement, but can be decomposed into two components - perpendicular and parallel to the line movements. The first component is dampened by the resistance of the support, and the second pushes the body forward.

Thus, the more bends, the greater the total driving force. Therefore, snakes that use this method of movement usually have a long, flexible and slender body. These are, for example, snakes and snakes - active snakes that track and catch up with their prey. Let us note, however, that the speed developed by the Snake even during the fastest gliding does not, as a rule, exceed 6-8 km per hour, and in many species it does not even reach 5 km per hour. Therefore, a person can easily catch up with any snake if the competition takes place on open space. Many readers are probably also interested in the opposite result: we can confidently guarantee that a snake cannot catch up with a person, even if it really wants to do so. However, this option is only of theoretical interest, since snakes never chase a person.

Since the serpentine type of movement uses support on the substrate, the efficiency of the movement depends on the roughness of the support. Thus, a snake cannot move on smooth glass: the body wriggles, but the animal remains in place. In addition to a smooth substrate, loose substrate - shifting desert sands not supported by vegetation - also provides poor support for the body. Under these conditions, some species of snakes (sand-tailed viper, tailed viper, horned rattlesnake) have developed a special type of movement - “lateral movement”. Indeed, looking at the moving faff, you are convinced that it is crawling not forward, but as if sideways. Pulling the back part of the body forward, she throws it forward without touching the substrate and then, leaning on the entire side of the body, pulls up the front part. With such a movement, the trail is not continuous, but consists of separate parallel strips with hooked ends, located at an angle to the line of movement. With this method of movement, the support is more solid, and the snake literally “steps” from one track to another.

This type of movement is asymmetrical, so the load on the muscles is uneven. To equalize it, the snake has to periodically change the “working side” of its body - crawl either with its left or right side forward. Some species of snakes do not pursue prey, but guard it, lying motionless in ambush. Such snakes are inactive, and their body is usually thick and short. They are incapable of graceful snake-like movements, and they have to abandon this method, switching to a rectilinear or caterpillar type of movement. It is especially pronounced in large and stubby African vipers (cassava, noisy viper).

The body of a crawling viper does not bend at all, and when viewed from above, it seems that it is simply floating on the surface. From the side, you can clearly see how a series of contractions and stretches runs along the abdominal side, moving the snake forward. The zigzag pattern on the sides of the body seems to come to life, its angles either decrease or increase, and it seems that the viper “walks” on a dozen pairs of short legs. In the movement of snakes, especially with the latter method, the expanded abdominal scutes play an important role. They can fit tightly to each other, forming a smooth surface, or by contracting the abdominal muscles, their posterior edge is lowered and good support is created. By maneuvering its ventral scutes, the snake can create traction or vice versa; provide gliding on different parts of the body. The importance of the ventral scutes is confirmed by the fact that sea snakes, living their entire lives in aquatic environment, lost them. Their belly is covered with the same small scales as their back. And so, if such a snake is pulled onto land, it wriggles, but is almost unable to move on the solid substrate. Burrowing, swimming and arboreal snakes have special specific adaptations for movement, which will be discussed when describing these species.

Snakes eat a wide variety of animals, from worms, mollusks and insects to fish, birds, rodents and small ungulates. All snakes are carnivorous, and the vast majority hunt live prey. Only individual species Sometimes they show a predilection for carrion (Persian viper, water muzzle). All snakes swallow their prey whole, without tearing or chewing it. The diet depends on the size of the snake; large species feed on correspondingly larger prey. The composition of food varies greatly with age: young individuals of most snakes feed on small invertebrates, and adults usually switch to feeding on vertebrates.

Only small species of snakes (blind snakes, contia, etc.) feed on insects, worms, etc. all their lives. Many snakes limit themselves to certain foods, and sometimes the specialization goes so far as to cause dramatic changes in the structure of the skeleton of the dental system. For example, in the African egg snake, which feeds only on bird eggs, the number of teeth has decreased and they have become small and blunt, and the processes of the vertebrae, perforating the esophagus, form a sharp “egg saw”, which serves to cut the egg shell. Thanks to the extensibility of the mouth and body coverings, snakes can swallow prey that is 2-3 times thicker than themselves. However, these abilities also have their limits, and even a 10-meter boa constrictor or python cannot swallow an adult horse or cow, as “eyewitnesses” often report after returning from distant travels.

The largest animals ever swallowed by boa constrictors reached the size of a pig or roe deer. Snakes swallow captured prey alive if it is small and does not offer strong resistance. For large and strong prey they are used various ways killing, primarily strangulation with body rings. This technique is used by boa constrictors and most colubrid snakes. It is important to note that when strangulated, the boa constrictor does not crush the ribs of its victim, as is often described. It compresses the victim just enough to paralyze its breathing movements. A broken rib in the body of the prey would be fatal to the snake itself, since when swallowed it would easily pierce the snake's highly stretched skin. Therefore, the victim enters the stomach not only whole, but also undamaged.

Special and very effective method killing prey has worked out Poisonous snakes. Poisonous species are present in the family of already-like animals, but their poisonous teeth are located in the depths of the mouth and reach the victim’s body only when it is strongly captured by the snake’s mouth. Therefore, such species are forced to hold onto captured prey. In sea snakes, adders, vipers and pit vipers, the poisonous teeth are located in front, so that these snakes, having delivered a quick bite and injected a portion of poison into the body of the victim, can release the victim and wait for the poison to have its disastrous effect. The emergence of the poisonous apparatus is undoubtedly associated with the most important feature snakes - swallowing large prey whole. Such prey must first be immobilized, and venom accomplishes this task in the most perfect way. In addition, introducing poison into the victim's body speeds up its digestion several times, since the poison from the inside destroys the tissues of the victim's body, preparing them for absorption.

Scientists have discovered why snakes crawl quickly

MOSCOW, February 18. The science for a long time could not find the answer to the question why snakes are able to move so quickly, because crawling is quite in a complicated way movement. It was believed that during bending, the snake’s body is repelled by unevenness on the ground and from various plants, which gives her the opportunity to crawl faster, writes Science.YoRead.ru.

Scientists have conducted a number of studies and refuted this opinion. They found that the secret to the snake's fast movement is the structure of its scales. The scales on the skin of the snake’s belly are located in such a way that they do not allow it to move towards the tail and to the side, thereby determining the forward direction as preferable. A similar method of movement is used in skiing and skating. Similar uneven friction in different directions of motion is usually called frictional anisotropy.

To prove their theory, the researchers built mathematical model movements of the snake, where they took the speed with which the center of mass of the snake moves as a function of the size and speed of the frictions that appear when its body bends.

The study of the constructed mathematical model proved that the scientists were right and showed that the scales help create inhomogeneous friction of the snake’s body on various surfaces, which helps the snake move quickly even on slippery surfaces.

It was previously reported that a snake with one clawed paw in the middle of the body, similar to the limb of a lizard or frog, was discovered in China. A strange mutant “showed up” at midnight in the bedroom of a 66-year-old resident of the city of Suining in the southwestern province of Sichuan. The snake, 40.5 cm long and as thick as a little finger, climbed along a vertical surface, deftly clinging to it with the claws of its only leg. The Chinese woman says she was very scared, but nevertheless had enough “courage” to beat the creature to death with a slipper. Moreover, after making sure that the snake was dead, the woman also placed it in a bottle of alcohol. Thanks to her almost professional actions, Chinese scientists acquired the mutant reptile and are already conducting the necessary research. One of them, a snake specialist, admitted to the newspaper that what he saw shocked even him. He hopes to find out the cause of the mutation only through the results of an autopsy.

The most common mutation among snakes today is “two-headedness.” It is formed according to the same principle as the doubling of body parts in Siamese twins. Such individuals have little chance of surviving in conditions wildlife- if only because both heads strive to attack each other every now and then.

About snakes and their movements

The movement of snakes is full of charming originality. The sight of a silently sliding writhing ribbon makes an indelible impression on the viewer and provides aesthetic pleasure. However, the typical so-called “snake” movement is by no means the only method that snakes use. In different living conditions, on different substrates, different snakes have developed a number of special types of movement. With the “serpentine” type of movement, the body bends in a wave-like manner and the resulting waves seem to run along the body from head to tail. The arching part of the body, placed obliquely to the direction of movement, rests on the substrate and creates a pushing force. It is directed at an angle to the movement, but can be decomposed into two components - perpendicular and parallel to the line of movement. The first component is quenched with resistance of the support, and the second pushes the body forward.

Thus, the more bends, the greater the total driving force. Therefore, snakes that use this method of movement usually have a long, flexible and slender body. These are, for example, snakes and snakes - active snakes that track and catch up with their prey. Let us note, however, that the speed developed by the Snake even during the fastest gliding does not, as a rule, exceed 6-8 km per hour, and in many species it does not even reach 5 km per hour. Therefore, a person can easily catch up with any snake if the competition takes place in an open space. Many readers are probably also interested in the opposite result: we can confidently guarantee that a snake cannot catch up with a person, even if it really wants to do so. However, this option is only of theoretical interest, since snakes never chase a person.

Since the serpentine type of movement uses support on the substrate, the efficiency of the movement depends on the roughness of the support. Thus, a snake cannot move on smooth glass: the body wriggles, but the animal remains in place. In addition to a smooth substrate, loose substrate - shifting desert sands not supported by vegetation - also provides poor support for the body. Under these conditions, some species of snakes (sand-tailed viper, tailed viper, horned rattlesnake) have developed a special type of movement - “lateral movement”. Indeed, looking at the moving faff, you are convinced that it is crawling not forward, but as if sideways. Pulling the back part of the body forward, she throws it forward without touching the substrate and then, leaning on the entire side of the body, pulls up the front part. With such a movement, the trail is not continuous, but consists of separate parallel strips with hooked ends, located at an angle to the line of movement. With this method of movement, the support is more solid, and the snake literally “steps” from one track to another.

This type of movement is asymmetrical, so the load on the muscles is uneven. To equalize it, the snake has to periodically change the “working side” of its body - crawl either with its left or right side forward. Some species of snakes do not pursue prey, but guard it, lying motionless in ambush. Such snakes are inactive, and their body is usually thick and short. They are incapable of graceful snake-like movements, and they have to abandon this method, switching to a rectilinear or caterpillar type of movement. It is especially pronounced in large and stubby African vipers (cassava, noisy viper).

The body of a crawling viper does not bend at all, and when viewed from above, it seems that it is simply floating on the surface. From the side, you can clearly see how a series of contractions and stretches runs along the abdominal side, moving the snake forward. The zigzag pattern on the sides of the body seems to come to life, its angles either decrease or increase, and it seems that the viper “walks” on a dozen pairs of short legs. In the movement of snakes, especially with the latter method, the expanded abdominal scutes play an important role. They can fit tightly to each other, forming a smooth surface, or by contracting the abdominal muscles, their posterior edge is lowered and good support is created. By maneuvering its ventral scutes, the snake can create traction or vice versa; provide gliding on different parts of the body. The importance of the ventral scutes is confirmed by the fact that sea snakes, living their entire lives in the aquatic environment, have lost them. Their belly is covered with the same small scales as their back. And so, if such a snake is pulled onto land, it wriggles, but is almost unable to move on the solid substrate. Burrowing, swimming and arboreal snakes have special specific adaptations for movement, which will be discussed when describing these species.

It should be noted that snakes rarely develop truly impressive speeds. Most species move no faster than eight kilometers per hour, but the black mamba, for example, can crawl at a speed of sixteen to nineteen kilometers per hour.

One of the main methods of movement is the accordion movement. The snake first gathers its entire body into folds, then, fixing the tip of its tail in one place, it pushes itself forward. After this, she pulls up the back of the body, gathering itself into folds again.

The second way to move is to move with a caterpillar. In this way, snakes move in a straight line and overcome some narrow places. With this method, the snake uses large scales located on its belly. She plunges them into the ground like small shovels. When the scale is in, the snake uses its muscles to move it towards the tail. As a result, the scales are pushed off the ground in turn, which allows the snake to move. This method is similar to rowing, which people use to move around in boats. The movement of the scales is similar to the movements.

Amazing sight

The characteristic writhing movement is used by snakes to move across fairly hard ground. To propel itself forward, the snake pushes against roots, stones, sticks and other hard objects, bending its body to the side. With this method of movement, the snake contracts its lateral muscles alternately, which allows it to crawl forward.

Such wave-like movements are the basis of snake crawling. From the outside, this spectacle is mesmerizing. The reptile seems to lie motionless, but at the same time it flows forward for the eye. This feeling of lightness and imperceptibility of movement is deceptive. Snakes are amazingly strong creatures, their smooth movements are ensured by synchronized and measured work of muscles.

The fourth type of movement is called lateral movement or twisting. It is characteristic mainly of snakes living in the desert. Using this type of movement, they move through loose sand, and they do it surprisingly quickly. The lateral move is so called because first the snake’s head moves diagonally forward and to the side, and only then it pulls up the body. First it rests on the back of the body, then on the front. This type of movement leaves strange parallel marks on the sand with characteristic hooks at the ends of the segments.

There are other ways snakes can move. Paradise snakes, found in Indochina, Indonesia and the Philippines, live on palm trees. If they want to change their habitat, they simply fly to another tree. In reality, of course, they jump. Before jumping, the paradise snake takes a very deep breath to create air chamber inside the body, which works as a parachute. This allows her to glide an impressive distance of up to thirty meters.

It is not known exactly when the legs disappeared during evolution in the ancestors of modern snakes, but on X-ray photographs one can still see rudimentary remains of the lower limbs.

Instructions

Because all snakes are active predators, the lack of legs did not affect their speed and agility. The limbs of snakes are replaced by scales that cover the body. Movements due to the adhesion of scales to the surface are divided into four main types.

Rectilinear movement (caterpillar). A group of scales on the ventral side of the animal pushes the snake’s body forward, plunging into the surface, like the oars of a boat; the remaining scales create a stop. So, one after another, the scales first protrude, then are pressed by the force of movement of a special group of muscles, and the snake moves forward.

Wave-like lateral movement (squirming). The snake’s body seems to flow sideways, and an alternating contraction of the lateral muscles of the body occurs. All points of the animal’s body in contact with the surface constantly perform a series of sequential movements: push, carry, support. Due to these movements, a picture of rapid and easy movement is created. The number of vertebrae in snakes reaches 435, therefore, the number of bending points is approximately the same. How longer than the snake, the more powerful and faster it can move.

Lateral movement (twisting). The head of the reptile goes sideways and forward, then the body is pulled towards it. When leaning on the front part of the body, the back part is brought forward, then the cycle is repeated in reverse. It feels like a snake is walking. This is how the sand f-hole moves.

About snakes and their movements

The movement of snakes is full of charming originality. The sight of a silently sliding writhing ribbon makes an indelible impression on the viewer and provides aesthetic pleasure. However, the typical so-called “snake” movement is by no means the only method that snakes use. In different living conditions, on different substrates, different snakes have developed a number of special types of movement. With the “serpentine” type of movement, the body bends in a wave-like manner and the resulting waves seem to run along the body from head to tail. The arching part of the body, placed obliquely to the direction of movement, rests on the substrate and creates a pushing force. It is directed at an angle to the movement, but can be decomposed into two components - perpendicular and parallel to the line of movement. The first component is dampened by the resistance of the support, and the second pushes the body forward.

Thus, the more bends, the greater the total driving force. Therefore, snakes that use this method of movement usually have a long, flexible and slender body. These are, for example, snakes and snakes - active snakes that track and catch up with their prey. Let us note, however, that the speed developed by the Snake even during the fastest gliding does not, as a rule, exceed 6-8 km per hour, and in many species it does not even reach 5 km per hour. Therefore, a person can easily catch up with any snake if the competition takes place in an open space. Many readers are probably also interested in the opposite result: we can confidently guarantee that a snake cannot catch up with a person, even if it really wants to do so. However, this option is only of theoretical interest, since snakes never chase a person.

Since the serpentine type of movement uses support on the substrate, the efficiency of the movement depends on the roughness of the support. Thus, a snake cannot move on smooth glass: the body wriggles, but the animal remains in place. In addition to a smooth substrate, loose substrate - shifting desert sands not supported by vegetation - also provides poor support for the body. Under these conditions, some species of snakes (sand-tailed viper, tailed viper, horned rattlesnake) have developed a special type of movement - “lateral movement”. Indeed, looking at the moving faff, you are convinced that it is crawling not forward, but as if sideways. Pulling the back part of the body forward, she throws it forward without touching the substrate and then, leaning on the entire side of the body, pulls up the front part. With such a movement, the trail is not continuous, but consists of separate parallel strips with hooked ends, located at an angle to the line of movement. With this method of movement, the support is more solid, and the snake literally “steps” from one track to another.

This type of movement is asymmetrical, so the load on the muscles is uneven. To equalize it, the snake has to periodically change the “working side” of its body - crawl either with its left or right side forward. Some species of snakes do not pursue prey, but guard it, lying motionless in ambush. Such snakes are inactive, and their body is usually thick and short. They are incapable of graceful snake-like movements, and they have to abandon this method, switching to a rectilinear or caterpillar type of movement. It is especially pronounced in large and stubby African vipers (cassava, noisy viper).

The body of a crawling viper does not bend at all, and when viewed from above, it seems that it is simply floating on the surface. From the side, you can clearly see how a series of contractions and stretches runs along the abdominal side, moving the snake forward. The zigzag pattern on the sides of the body seems to come to life, its angles either decrease or increase, and it seems that the viper “walks” on a dozen pairs of short legs. In the movement of snakes, especially with the latter method, the expanded abdominal scutes play an important role. They can fit tightly to each other, forming a smooth surface, or by contracting the abdominal muscles, their posterior edge is lowered and good support is created. By maneuvering its ventral scutes, the snake can create traction or vice versa; provide gliding on different parts of the body. The importance of the ventral scutes is confirmed by the fact that sea snakes, living their entire lives in the aquatic environment, have lost them. Their belly is covered with the same small scales as their back. And so, if such a snake is pulled onto land, it wriggles, but is almost unable to move on the solid substrate. Burrowing, swimming and arboreal snakes have special specific adaptations for movement, which will be discussed when describing these species.

Methods of transportation

It may seem that it is very difficult to move without legs, but snakes do it masterfully. In fact, they know how to move on land in four main ways. If one method is not suitable, then they use another. Sometimes, especially on a very flat surface, they have to try all four methods. The crawling of snakes can be quite rapid, and some of them are even capable of chasing their prey. However, even the fastest snakes rarely reach speeds exceeding 8 km/h. The crawling speed record is 16-19 km/h and belongs to the black mamba.

1. Accordion movement
One way the snake moves is called an accordion movement. First, the snake gathers its body into folds. Then, holding the tip of the tail in place, he pushes the front of the body forward. And finally tightens the back of the body.

2. Track movement
With the help of the caterpillar movement, the snake can move in a straight line. She uses this movement when she needs to overcome some bottleneck. At the same time, the snake moves large scales located on its belly. One by one, the scales sink into the ground like small shovels. As soon as the scales sink into the ground, the muscles move them towards the tail. One by one, the scales are repelled from the ground, and due to this, the snake moves. This is the same method people use when they row while on a boat. They plunge their oars into the water just as snakes plunge their scales into the ground.

3. Twisting movement
Designed to move on hard ground. To move forward, the snake bends its body to the side, resting against stones, roots, sticks or other hard objects. During this movement, snakes alternately contract the muscles on their sides, so that their body bends in an S-shape: the snake wriggles and crawls.
Wave-like bending of the body is the most common way of snakes crawling. A calmly crawling snake is an amazingly beautiful and bewitching sight. Nothing seems to happen. The movements are almost imperceptible. The body seems to lie motionless and at the same time quickly flows. The feeling of ease of movement of a snake is deceptive. In her amazingly strong body, many muscles work synchronously and measuredly, moving the body precisely and smoothly. Each point of the body in contact with the ground alternately finds itself in the phase of either support, push, or forward transfer. And so constantly: support-push-transfer, support-push-transfer... The longer the body, the more bends and the faster the movement. Therefore, during the course of evolution, the body of snakes became longer and longer. In this regard, they are record holders among vertebrate animals. The number of vertebrae in them can reach 435 (in humans, for comparison, only 32-33).

4. Twisting or sideways movement- This is a method of movement that is used only by some species of snakes living in the desert. Using this method, they can move quickly through loose sand, and they move so quickly that it is difficult to follow them. In this case, the snake’s head goes sideways and forward, and then the body is pulled up. Snakes begin to almost walk, if one can say so about completely legless creatures: leaning on the back part of the body, they carry the front part forward, then vice versa.
In this case, very strange marks appear in the form of oblique parallel stripes with hooks at the end. You wouldn’t immediately guess that such a mark could be left by a living creature! It is in this way that the sand epha, a very dangerous snake that lives here in Central Asia, moves.

In addition to these methods, there are still some very unusual movement techniques. For example, in Indonesia, Indochina, and the Philippines, snakes from the genus Chrysopelea, a subfamily of false snakes, live. They are called heavenly for their grace and beauty. The paradise snake lives on palm trees, where it feeds on lizards. And if she wants to change her place of residence, she flies to another palm tree. When flying, its body takes on an S-shape, and its tail serves as a rudder. Before jumping, the snake takes a deep breath, forming an air chamber inside its body that serves as a kind of parachute and allows it to glide over a distance of up to 35 meters.

Some snakes are even capable of jumping forward, first gathering their body into rings, like a spring, and then sharply straightening it.

Snakes don’t have legs or even their rudiments, but how do they manage to “run” so fast? Interest Ask. The snakes, having lost their limbs, returned to their old method of movement. It seems to us that the snake moves with the help of its abdominal scutes, catching them on the ground. But this is not true. Carefully observing the movement of the snake and having studied decanally the methods of its movement, it was found that they move in a very specific way, using the movement of the whole body. The snake bends its body in a horizontal plane, creating waves of bends that continuously follow from front to back, creating a force that moves the snake forward.

A perfectly flat surface serves as an obstacle to the movement of the snake. Snakes cannot crawl on glass or . But if there is even the slightest roughness, then movement is quite possible. According to this principle, snakes “walk” on the sand. When bending the body, the loose sand moves and forms folds, which help movement. True, the speed of movement is very slow.

When moving on a smooth surface, friction occurs between the front part of the body and the soil (static friction), the snake collects the body into an accordion and pulls its back part forward - sliding friction is less than static friction. Then, leaning on the tail of the snake, the front part of the body lunges forward and again contracts into an accordion. This method of movement is used by large snakes with a heavy and strong body. This is how boas, snakes and vipers “walk”.

There is another way for a snake to move. It is based on the difference between static friction and sliding friction. When crawling this way, the snake does not bend, and its body remains straight. Part of the scutes on its belly is fixed to the soil, and the other part is pulled forward by muscles. The movable shields are fixed, and those that were not movable are tightened. This “straightforward” method of movement is used by snakes with short and thick bodies, some of them are boas and blind snakes.

Both described methods of movement of snakes do not allow them to crawl quickly, although they allow them to overcome smooth surfaces. To move quickly, snakes use “lateral movement.” The lateral method of “walking” of snakes can only be observed in them, and other animals use other methods when moving.

When moving sideways, the snake, lying on the ground or sand, raises its head, and then the front part of the body, bends it at a right angle and places it in a new place. The emphasis is placed on two points, the snake does the same with the rest of the body, so in parts it moves its body forward and to the side as it moves. During such movement, traces remain in the sand in the form of imprints of the snake’s body; they are directed obliquely to the direction of movement. This is how snakes of the species walk - horned vipers, ephas, rattlesnakes that live in the sands.

Snakes rely much more on the friction provided by their scales to move than on inertial forces. The work, carried out by physicists from the Georgia Institute of Technology, helped to understand how reptiles manage to move on a surface on which there is nothing to push off from.

It is believed that the snake crawls due to its wave-like movement. Other studies have shown that snakes are often repelled by objects that they encounter on their way (stones, branches, small tubercles on the surface of the earth). However, very little was known about how they managed to move on fairly smooth surfaces (sand, asphalt).

Scientists have also known for a long time that snakes move better forward and worse backward, but no one has ever tried to determine whether they are capable of sliding to the side.

Using polarized light shining through gelatin, scientists were able to figure out where the snake applies its greatest forces(photo by David Hu and Grace Pryor).

And David Hu and his colleagues decided to check it out. Physicists wanted to measure whether snake scales have lateral friction. To do this, they lowered a dozen king snakes Campbell ( Lampropeltis triangulum campbelli). First head forward, then tail, and then sideways. In the first part of a fairly simple experiment, snakes slid along rough fabric, in the second, on less rough cardboard.

And if on a smooth surface the snakes moved equally in almost all directions, then the fabric “slowed down” the lateral movement the most (that is, it was the lateral friction that was greatest).

When physicists used this data in their mathematical model, the “theoretical” snake slithered along almost the same trajectory as real snakes.

However, the speed of movement of the model and real snakes was very different.

After racking their brains a bit, scientists came to the conclusion that real snakes, among other things, redistribute their body weight depending on which parts rub harder (and therefore slow down their movement).

Special fabric bags placed over the snakes’ bodies helped to determine that these reptiles cannot move without the help of scales that “cling to the ground” (pictured on the right). Hu compares the scales to the blades of skates, which are easy to move forward and backward, but almost impossible to move sideways (photo by David Hu).

After making appropriate changes to the mathematical model, the “theoretical” snake began to move 35% faster. And this value was much closer to the speed of movement of real Campbell's king snakes.

Having measured the ratio of inertial forces and friction forces, the Americans came to the conclusion that the latter make an order of magnitude greater contribution to the movement of reptiles.

This theoretical research has very real applications. Many scientific groups are creating robotic snakes. And it is important for them to learn more about how real reptiles move.

Some robotic mechanisms have wheels that prevent sideways movement. However, if robot developers find a material with the same properties as snake scales, then perhaps wheels can be abandoned.

More information about the study can be found in

The key to snakes' agility (hundreds of vertebrae and ribs) is closely related to the key to their movement - the ventral scales. These specialized rectangular elements line the underside of the body, corresponding directly to the number of ribs. How does a snake crawl? The lower edges of the ventral scales function like the tread on a tire, gripping the surface and propelling the reptile forward.

Form and function

The most characteristic aspect of the snake form is its elongated body and tail, and lack of limbs. There are still snakes in the world in which the remains of the limbs still retain the function of movement, but complete or reduced elements of the pelvis and femur remain in many families, including the boa and python. The body is usually slender, although there are some comparatively short and stout species.

Body shape correlates with activity level, with thin types moving all the time and heavy forms being sedentary. Vipers, for example, although not always long, are often large. It seems likely that these snakes evolved in the direction of gravity only after the development of heat-sensitive skills, a loreal pit, a special organ located between the eye and nostril, and a venom apparatus, which allowed them to remain in one place and wait for their prey, rather than engage in continuous active search food.

Some of the largest snakes (boas, anacondas and pythons) have pit labialis that function similarly to the pit viper's loreal pit, so they may not be very mobile or large either. Tree snakes are the most elongated and slender of all, with a tail that takes up half the length of the entire body. The body is strongly compressed laterally, which allows for increased rigidity of the body frame while crawling from branch to branch. Burrowing snakes are rarely large. The tail of sea serpents is flattened to form an oar, used to row through water masses. Sea snakes They are almost completely helpless on land and can only move with great difficulty.

Snake structure: skeleton

The vertebral column of snakes is highly elongated and has more vertebrae than any other living animal - up to 600 Australian python(Morelia oenpelliensis). Since there are no limbs associated with the skeleton, and there are no good separators of body regions, snakes are generally considered to have only two types of vertebrae: the body (precaudal) and the caudal (caudal). There are 100-450 vertebrae in the body, 10-205 in the tail. A pair of ribs are connected to every vertebra of the body, except for a few just behind the head.

The way a snake crawls is determined by the structure of its body. There are no ribs on the caudal vertebrae. This allows lateral and vertical rotation without intertwining of the spinal column, thus achieving increased flexibility. The vertebra may bear on its ventral surface a long posteriorly directed projection called the hypapophysis. The presence or absence of this structure on the vertebrae of the posterior third of the body has great importance in the classification of snakes, because large groups species show this as a general characteristic.

Leather

The skin of a snake is covered with scales, which are keratinized folds in the epidermal layers of the skin. These scales are usually arranged in rows along the body, the appearance and arrangement of which are characteristic of certain type. They can be large and shield-shaped, in which case the number of rows is small (from 10 to 30), or they can be very small, round and sometimes with a raised center, in which case the number of rows can reach 180.

The snake's skin may be very smooth and shiny (like rainbow snakes), have a raised ridge (keel) along its center, be heavily striped, or even have a raised spine in the center, like the Java warty snake. The scales of some species have sensory structures. On the ventral surface of the body, in most forms it is modified into wide plates and is used for movement.

Methods of movement of snakes

Snakes have four modes of locomotion. Since they don't have legs, they use their muscles and skin to "walk".

• Snake method: repulsion from the surface, stones, trees. They move in wavy movements. A slippery and smooth surface, such as glass, is not suitable for this method. This movement is known as lateral undulation. Starting from the neck, the snake flexes its muscles, pushing its body from side to side, creating a series of curves. In water, this movement easily propels the snake forward because each contraction pushes against the water. On land, the snake will usually find points of resistance on the surface, such as rocks, branches or dents, and use its body to press on all the points at once, pushing the snake forward.
• Flattening method: it is more hard way for movement, but is effective in tight spaces. This method works well for horizontal surfaces, but snakes are raised using the accordion technique. The snake extends its head and front part of the body along the vertical surface, and then finds a place to grab the ventral scales. To reach, it grasps the surface with tufts in the center of its body, pulls it back to the end, and then returns forward again to find a new place to grab.
• Side kick: This is a difficult movement that snakes often use to navigate loose or slippery surfaces such as sand or mud. The muscle-squeezing and body-throwing side kick creates an S-shape that only has 2 points of contact with the ground. The snake seems to throw its head forward, and the rest of its body rushes after it.
• Straight-line (caterpillar) method: This is a slow, crawling, straight movement. How does the snake crawl? The animal uses some of the broad scales on its abdomen to grip the ground as it propels itself forward. This is a much slower method of travel, the waves are much smaller and curve up and down rather than side to side. When a snake uses caterpillar locomotion, the tops of each curve rise above the ground while the ventral scales on the bottoms push against the ground, creating a ripple effect similar to that of a caterpillar.

Can a snake crawl in the opposite direction?

Birds don't fly backwards, fish don't swim, antelopes don't run backwards. This also applies to reptiles. How does a snake crawl? Each part of the abdomen has its own muscles, which the snake can use to propel itself forward. Can snakes move in a straight line? Yes, they can, but it depends on the type of surface they have to crawl on, their speed and various other external factors. The only reason why this is not commonly seen in most snakes is because it is simply not necessary.